Production of nitriles

ABSTRACT

Nitriles are produced by reaction of hydrocarbon and ammonia in the presence of a supported metal oxide, wherein the support has a surface area greater than 50m2/gm, and a porosity greater than 0.4 cc/gm. The metal oxide is present in the pores of the support in an amount from 25% to 75%, by weight.

United States Patent 1191 Gelbein Dec. 9, 1975 [5 1 PRODUCTION OFNITRILES 2.833.807 5/1958 Farkas 6161. 328/122 3.231.600 l 1966 J i l.[75] Invent Abraham Gelbein, Plamfield, 3,278.573 10/1966 132:); :1 a1260/465 l 3.525.l0l 8/!970 Young et a]. 260/4653 [73] Ass'gnee LummusCompany Bloomfie 3.544.617 12/1970 Oga et al. 260/465 [22] Filed: Apr.24, 1974 [21] Appl. No: 463,758 Primary Examiner-Lewis Gotts AssistantExamt'nerDolph H. Torrence Related Apphcauon Dam Attorney, Agent, orFirmMam & Jangarathis [60] Division of Serr No. 147,159. May 26. l97l,which is a continuation-impart of Ser. No. 803.874. Feb. 27. I969.abandoned.

[52} US. Cl 260/465 C; 252/451; 252/454; {57] ABSTRACT 252/459; 252/460;252/461; 252/462; 252/463; 252/464; 252/465; 252/466 R; Nitnles areproduced by reactlon of hydrocarbon and 252/467; 252/472. 260/4653ammonia in the presence of a supported metal oxide. 1511 1m. (:1. C07C120/14 wherein the Support has a Surface area grew [58] Field 61 Search260/465 (3. 465.3 SOmz/gm, and a Pomsity greater than CC/gm- The metaloxide is present in the pores of the support in an 5 References Ciedamount from 25% to 75%. by weight.

UNITED STATES PATENTS 2.540.788 2/1951 Klimitas et a] 1. 260/465 11Claims, No Drawings PRODUCTION OF NITRILES This application is adivision of US. application Ser. No. 147,159, filed on May 26, l97l,which is a continuation-in-part of US. application Ser. No. 803,874,filed on Feb. 27, 1969 and now abandoned.

This invention relates to the production of nitriles by the use ofsupported metal oxides.

Supported metal oxides are well-known catalysts for a wide variety ofchemical reactions. In general, such catalysts are comprised of a metaloxide coated on a support material of low porosity and low surface area,commonly referred to as an inert support. The method generally employedfor producing such metal oxide catalysts involves impregnating the inertsupport with a solution of a soluble salt of the metal oxide, separatingthe saturated solid and heating to remove a major portion of thesolvent. The support is then calcined to convert the metal salt to thecorresponding oxide. In some cases, a multiple impregnation technique isemployed to achieve a higher concentration of metal oxide on thesupport.

Another technique employed for forming supported metal oxide catalystsinvolves suspending the support material in a solution of a salt of thetransition metal, completely or partially evaporating the solvent andpossibly mixing of the resultant material with an organic binder andpelletizing thereof. The dried pellet is then heated to an elevatedtemperature to effect complete dehydration and burning out of theorganic material.

A further method for forming a supported metal oxide on an inert supportis disclosed in US. Pat. No. 2,977,324 which involves contactingparticles of a porous support material with the molten metal oxide toproduce a catalyst in which the metal oxide is embedded in the porestructure.

US. Pat. No. 3,278,573 discloses a supported metal oxide catalyst inwhich the metal oxide is supported on a support of high porosity andhigh surface area. The catalyst, however, is prepared by an impregnationtechnique.

US. Pat. No. 2,838,558 discloses a supported metal oxide catalyst inwhich the metal oxide is supported on a heat treated activated alumina.

The supported metal oxide catalysts heretofore produced in the art,although suitable for many applications, do not possess the combinationof activity, selectivity and structural strength that is desired forsome applications.

Accordingly, an object of this invention is to provide a new andimproved supported metal oxide.

Another object of this invention is to provide a supported metal oxidecatalyst having improved activity, selectivity and structural strength.

A further object of this invention is to provide a supported metal oxidecatalyst in a facile operation at low cost.

Still another object of this invention is to provide a new and improvedprocess for producing nitriles.

These and other objects of the invention should be more readily apparentfrom the following detailed de scription thereof.

The objects of this invention are broadly accomplished by supporting themetal oxide on a support of high porosity and high surface area (anactive support) in a manner such that the metal oxide is present in anamount from about 25% to about 75%, preferably from I mentioned:silica-alumina,

about 30% to about 60%, all by weight, substantially entirely within thepores of the support; i.e., the support is continuous in that eachparticle of the product has an uninterrupted lattice of the supportmaterial. Thus, the weight ratio of metal oxide to support which issubstantially entirely within the pores of the support ranges from about0.3:l to about 3:l preferably from about 0.411 to about l.5:l. Thesupported metal oxide in which the metal oxide is substantially entirelywithin the pores of the support, as hereinafter described in moredetail, is preferably prepared by contacting the support material withmolten metal oxide for a time sufficient to draw the metal oxidesubstantially entirely within the pores of the support.

The support on which the metal oxide is to be supported has a surfacearea of greater than about 50m /gm and a porosity greater than about 0.4cc/gm. in general, the surface area of the support is no greater thanabout 600m /gm and the porosity is no greater than about 1.2 cc/gm.Supports having a surface area of about 200m /gm have been found toprovide particularly good results. As representative examples ofpreferred supports having such properties, there may be zeolites,alumina, including microcrystalline and the 'y, 5, 'n, K, and Xmodifications of alumina. The surface area of the support, after placingthe metal oxide substantially entirely within the pores of the support,is generally from about 5 to about 15 m lgm, and in particular, about 10m /gm.

The metal oxide supported in the pores of the support may be comprisedof one or more metal oxides, and as representative examples of suchmetal oxides, there may be mentioned oxides of the following metals;metals having atomic numbers 21 through 33, 39 through 5 l 72 through83, 57 through 71 (in particular cerium), and 92. If more than one ofthe hereinabove noted metal oxides is used, such metal oxides may bepresent as discrete phases and/or such metal oxides may combine witheach other whereby the metal oxides are present within the pores of thesupport in a combined form; i.e., a form other than as discrete metaloxide phases. Similarly, one or more of the hereinabove noted metaloxides may be combined with a compound other than the noted metal oxidesin which case such one or more metal oxides may be present in the poresin the support in a combined form; i.e., other than as a discrete metaloxide.

Thus, for example, a catalyst fonned from molybdenum, phosphorous andlithium oxides may be present as discrete phases of M00 P 0 and U 0 ormay be combined in the form of a so-called heteropoly salt [Li (PMo O Hwhich is stoichiometrically equivalent to Li PO .12MoO [t is to beunderstood that the term metal oxide as used in the specification andclaims is intended to include such combined forms of metal oxides,whether combined after being placed in the pores of the support orcombined externally to the support and subsequently placed into thepores of the support, with the metal oxides hereinabove described,whether as a discrete phase or in a combined form, being present in theamount specified.

in most applications wherein the supported metal oxide is to be employedas a catalyst, the particle size distribution of the support shouldcorrespond to that of the desired catalyst since the added metal oxidedoes not materially change the particle size of the resulting product inthat the metal oxide is substantially entirely within the pores of thesupport. The supported metal 3 oxides of the invention are particularlysuitable for use as fluidized solids and consequently are generallyproduced as fine powders with a rather wide particle size distributionbeing preferred, generally centering in the 30 to about 200 mesh range.

The supported metal oxides are preferably prepared by thoroughly mixinga powdered metal oxide with a powdered support in the proportionsdesired for the final product, i.e., from about 25 to about 75%,preferably from about 30 to about 60%, all by weight, of metal oxide,until a uniform mix is obtained. The mixture is then heated to atemperature above the fusion temperature of the metal oxide, preferablyin an oxygen-containing atmosphere, and maintained at this temperaturewhile the metal oxide is drawn into the pores of the support. generallya period of time from about i to about 10 hours. The exact temperatureemployed is dependent upon the fusion temperature and fluidity of themetal oxide or mixture of metal oxides employed and on the temperaturestability of the support. In general, the temperature need not begreater than about 150C. above the fusion temperature of the metaloxide(s) and should not exceed about l500C.

In cases where the oxide of the metal(s) are highly refractory; i.e.,have a fusion temperature greater than about l500C., the metal may bedeposited in the pores of the support in an inert atmosphere; i.e.,non-oxidizing atmosphere, as a metal salt having a fusion temper atureless than about l500C., followed by in situ treatment to convert thesalt to the metal oxide. Thus, for example, the oxides of: titanium,manganese, iron, nickel, zinc, gallium, yttrium, zirconium, tin, hafniumand tantalum have fusion temperature about l500C. and these metals aredeposited in the pores of the support as a salt having a fusiontemperature below about 1500C.; e.g., as the corresponding chlorides,followed by hydrolysis and calcination, in situ, to produce the metaloxide. it is also to be understood that a metal oxide or mixture ofmetal oxides having a fusion temperature less than about l500C. may alsobe deposited in the pores of the support as a corresponding salt,followed by appropriate treatment in situ to produce the metal oxide.

The supported metal oxide(s) may be prepared by any one of a widevariety of procedures. Thus, for example, the metal oxide(s) may beadded continuously or incrementally to a preheated support, and in aparticularly preferred procedure, metal oxide(s) and support arecontinuously added to one end of a heated kiln or similar device andsupported metal oxide withdrawn from the other end thereof. The supportis preferably maintained as a free flowing powder with the metaloxide(s) being drawn into the pores of the support by a capillaryaction.

The following Examples illustrate procedures for preparing supportedmetal oxides of the invention, but it is to be understood that the scopeof the invention is not to be limited thereby:

EXAMPLE I Powdered V,O, 180 g.) was blended with 270 g. ofmicrocrystalline gamma-alumina (Harshaw Al 140] P, 97% Al,0 pore volume0.5 cc/g, surface area 200 mlg, avg. particle size approx. 50 microns)in a rotating blender until a uniform mix was obtained (about l5 minutesmixing time required). The mixture was then heated to 695C. in air in amuffle furnace and kept at this temperature for 3 hours. During thistime, the V 4 (mp. 690C fused and was drawn into the support. Theresulting catalyst was cooled, screened, and contained 40 wt. V 0

EXAMPLE ll The procedure of Example I was repeated except that thesupport was silica-alumina (a fluid cracking catalyst having 87% SiO l3%A1 0 a pore volume of 0.75 cc/g.; a surface area of 200 m lg; an avg.particle size of 60 microns, sold under the trademark AEROCAT) and theheating time was 5 hours.

EXAMPLE Ill The procedure of Example ll was repeated except that 40 wt.M00 was used instead of V 0 and the fusion temperature was 400C.

EXAMPLE IV The procedure of Example I was repeated using 16 wt. V 0 and24 wt. M00 as the metal oxide.

EXAMPLE V The procedure of Example I was repeated using 24 wt. V205 andM003.

EXAMPLE Vl Chromic acid (CrO is blended with Aerocat fluid crackingcatalyst (50 wt. and the mixture heated to 250C. (CrO melts at 197C.) inair in a muffle furnace and kept at this temperature for 1 hour. Thetemperature is then raised to 700C. and maintained for 3 hours toconvert the CrO in situ to Cr 0 The resulting catalyst contains 40 wt.Cr 0 EXAMPLE VII Co(NO,-,),.6H,O is melted at 5060C. and blended withAerocat fluid cracking catalyst (53 wt. of the cobaltous nitrate)preheated to ca. C. until all the cobaltous nitrate is drawn into thepores of the support. The resulting product is then maintained at 600C,to convert the cobaltous nitrate to cobaltic oxide (CO,O The resultingproduct is supported cobaltic oxide containing 30 wt. of the oxidesubstantially entirely within the pores of the support.

EXAMPLE VIII The procedure of Example I is repeated using 40 wt.antimony oxide at a fusion temperature of 800C. The resulting productcontains 40 wt. antimony oxide substantially entirely within the poresof the sup port.

EXAMPLE lX Powdered cerous chloride (CeCl is blended with Aerocat fluidcracking catalyst (43 wt. CeCl and the mixture heated to 850C. (CeClmelts at 822C.) under a nitrogen atmosphere for 1 hour. The temperatureis then increased to l00OC. and maintained at this temperature for 3hours in a hydrogen-containing atmosphere wherein the CeCl is convertedto cerous hydride. The temperature is then reduced to 300C. andmaintained for 3 hours in an oxygen-containing atmosphere which convertsthe cerous hydride to ceric oxide (CeO The resulting product issupported ceric oxide containing 30 wt. of the oxide substantiallyentirely within the pores of the support.

EXAMPLE X Powdered tungsten bromide is blended with Aerocat fluidcracking catalyst (43 wt. tungsten bromide) and the mixture heated to300C. under a nitrogen atmosphere for 1 hour. The resulting product isheated to a temperature of 400C. in a hydrogen-containing atmosphere toconvert the tungsten bromide to tungsten metal which is then heated to800C. in an oxygen-containing atmosphere to produce the tungsten oxide.The resulting product contains 30 wt. of the tungsten oxidesubstantially entirely within the pores of the support.

The preparation of the supported metal oxide(s) has been hereinabovedescribed with respect to the preferred fusion technique. It is to beunderstood, however, that the scope of the invention is not to belimited thereby in that other methods for providing supported metaloxide(s) containing 25-75 wt. metal oxide substantially entirely withinthe pores of the support are also possible.

The catalysts of the present invention in which the metal oxide isplaced in the amounts specified into the pores of an active support arean improvement over the supported catalysts of the prior art. Thus, forexample, the catalysts of the present invention are an improvement overthose in which the metal oxide is placed in the pores of a support oflow porosity and low surface area (an inert support), such asalpha-alumina. The catalysts of the present invention are also animprovement over those in which a metal oxide is impregnated on anactive support. The catalysts of the present invention are unexpectedlymore active than prior art supported catalysts, as evidenced by bothimproved selectivity and conversion, as hereinafter noted in ExampleXII. These results are considered to be particularly unexpected in thaton the basis of prior art knowledge, it would be expected that the useof a fusion technique would mask the support and derogate from anybenefit which would be expected to result from the use of an activesupport.

The supported metal oxides of the invention are quite distinct fromthose heretofore known in the art in that they have improved catalystactivity, selectivity and im proved structural strength. Although theinvention is not to be limited by any theoretical reasoning, it isbelieved that such improvements result from the fact that unlikeprevious supported metal oxides the metal oxide is present as a deepcontinuous film on a continuous support, permitting free migration ofoxygen and/or electron holes or electrons to and from the surface. Thesupported metal oxides prepared by simple impregnation techniques do notcontain the high concentration of metal oxides which are present in thesupported metal oxides of the present invention; i.e., the prior artsupported metal oxides contain less than 25% metal oxide, and thereforehave thin and/or discontinuous films of the metal oxide, resulting inpoor electron migration and incomplete coverage of the support. Thesupported metal oxides prepared by a multiple impregnation techniquestill do not contain the high metal oxide concentrations of theinvention and in addition the interface between metal oxide layersoffers resistance to electron migration.

The supported metal oxides produced by these impregnation techniques,have a lower attrition resistance than the supported metal oxides of theinvention because the former have a high content of metal oxide on 6 theoutside surface of the support. This is particularly disadvantageous inthat the attrition causes intolerable pressure drop in static beds andloss of fines in exit gases from fluidized beds.

The supported metal oxides of the invention may be employed in any oneof a wide variety of chemical reactions. Thus. for example, thesupported metal oxides of the invention; in particular the oxides of thefollowing metals: thorium, uranium, bismuth, molybdenum. titanium,vanadium, tin, chromium. tungsten, cobalt, iron, manganese, copper,arsenic, antimony, etc, may be employed for the production of nitriles,in particular aromatic nitriles from alkyl substituted aromatic hydrocarbons and aliphatic nitriles from olefinically unsaturated aliphatichydrocarbons.

The hydrocarbon is contacted with ammonia in the vapor phase in thepresence of the supported metal oxide, either in the absence or presenceof a free-oxygencontaining gas, preferably in the absence of oxygen. Thecontacting is generally effected at temperatures from about 300C. toabout 500C, preferably from about 350C. to about 450C, with the contacttime generally ranging from about 0.1 to about l0 seconds,

- preferably from about 0.5 to about 2 seconds. The reaction pressuresgenerally range from about 1 to about 5 atmospheres. The mole ratio ofammonia to hydrocarbon generally ranges from about 1:1 to about 1011,preferably from about 2:1 to about 5:l. If an oxygencontaining gas isemployed in the feed, the gas is employed in an amount such that thequantity of oxygen and hydrocarbon in the feed is outside the explosiverange. It is to be understood that the hereinabove described conditionsare only illustrative and the choice of optimum conditions will varywith the particular re actants and supported metal oxide. The choice ofoptimum conditions is considered to be within the scope of those skilledin the art.

In accordance with a preferred embodiment, the hydrocarbon and ammoniaare contacted in the absence of oxygen and the supported metal oxide isemployed in a fluidized condition. In the preferred embodiment, thesupported metal oxide is periodically passed to another reactor (ingeneral the supported metal oxide is not maintained on-stream for aperiod greater than 30 minutes, preferably from about 2 to about 10minutes) and contacted therein with a free-oxygen-containing gas for aperiod'of time ranging from about 2 to about 20 minutes. The supportedmetal oxide is then recycled to the nitrile production zone. Althoughapplicant does not intend to limit the invention by theoreticalreasoning, it is believed that the supported metal oxide is reducedduring the nitrile production step and consequently periodic oxidationthereof is required to maintain the supported metal oxide in theoxidized form necessary for the nitrile production.

The hydrocarbon starting material may be an alkyl substituted aromatichydrocarbon, with the aromatic nucleus being either benzene ornaphthalene, and in particular benzene, and may contain two or morealkyl groups in which case the resulting product is a polyni trile. Thealkyl group generally contains no more than 4 carbon atoms, preferablyno more than 2 carbon atoms. As representative examples of suitablealkyl substituted aromatic hydrocarbons there may be mentioned: toluene;the various xylenes to produce the various phthalonitriles; ethylbenzene; trimethyl benzenes', methyl naphthalenes; and the like. It isto be understood that a mixture of such compounds may be employed inwhich case the reaction effluent contains a mixture of nitriles. Thehydrocarbon starting material may also be an olefinically unsaturatedaliphatic hydrocarbon, in particular propylene and isobutylene, in whichcase the products are acrylonitrile and methac rylonitrile,respectively.

The invention is further illustrated by the following Examples but thescope of the invention is not to be limited thereby.

1O EXAMPLE XI The feeds tabulated below were contacted in the presenceof 75 g.-9O g. of the supported metal oxides of Examples I and 11through V at temperatures of 430C460C and a contact period of 0.6seconds. In Case 1, oxygen was present in the feed gas while in Case 11,the feed was free of oxygen, with the metal oxide being periodicallyregenerated in a separate zone by contact with an oxygen-containing gas.

port provides improved conversion and selectivity as compared to both ametal oxide impregnated on an identical support and a metal oxide placedsubstantially entirely within the pores of an inert support.

The supported catalysts of the present invention provided improvedresults in the production of nitriles as a result of their superioractivity. Thus, the catalysts of the present invention are effective forthe production of nitriles in the absence of oxygen, which permitsgreater flexibility in that there is no possibility of explosivemixtures. In addition, in accordance with the present invention,nitriles can be effectively produced at lower ammonia to hydrocarbonfeed ratios; i.e., the prior art indicates that the use of an activesupport requires ammonia to hydrocarbon feed ratios of around 20:1,whereas, in accordance with the present invention, nitriles can beproduced at ammonia to hydrocarbon feed ratios in the order of 4:1.

The supported metal oxides of the invention may be used for any of awide variety of purposes generally known in the art. Thus, for example,as hereinabove 01 N1 noted supported metal oxides may be employed in theCase 1 4.2 17.2 8.6 32.4 37.8 production of nitriles. In addition,supported metal ox- 681 ides are useful as catalysts in dehydrogenationreactions and/or oxidation reactions and/or hydrogenation reactions.Thus, for example, the supported oxides of Conversion Space Yield lb.Selectivity to terephthalonitrile Catalyst Case Mol. TPN/hr-lb cat. andp-tolunitrile Mol. 1 t 54 0.35 87 n 63 0.43 84 m l 29 0.17 80 IV I 0.2686 u 46 0.31 85 v n 34 0.23 85 "Total nitrile groups produced.calculated as terephthalonitrile The results indicate that reaction inthe absence of oxygen results in higher conversion and productivitywithout decrease in yield.

EXAMPLE XII A. A catalyst was prepared as described in Example I of thisapplication, except that the support is alphaalumina.

B. A catalyst having 10 wt. V 0 impregnated on the support of Example Iof this application was prepared by the impregnation technique ofExample I of US. Pat. No. 2,838,558 (the active support was not heattreated).

A feed comprised of 4.3 mole p-xylene, 17.0 mole ammonia; 68.1 molenitrogen; and 10.6 mole water, is contacted with 75 grams of thesupported metal oxides, designated A and B above and the supported metaloxide of Example I at a temperature of 850F. and a contact time of 0.6seconds. The results were as follows:

Selectivity to Conversion Space Yield lb. terephthalonitrile M01.TPNlhr-lb cat. and p-tolunitrile A 26 0.13 61 B 22.3 0.12 68 Ex. I 630.43 84 The results indicate that a supported metal oxide of the presentinvention in which the metal oxide is placed substantially entirelywithin the pores of an active supvanadium, silver, copper, manganese,nickel, molybdenum and tungsten may be employed for the production of:olefin oxides, (ethylene to ethylene oxide); anhydrides (butene tomaleic anhydride; o-xylene to phthalic anhydride); and carboxylic acids(propylene to acrylic acid) and the supported oxides of chromium, zinc,manganese, iron, copper, zirconium, cerium and cobalt may be employedfor the production of olefinically unsaturated compounds (propane topropene; butene to butadiene', ethyl benzene to styrene). The supportedmetal oxides of the invention may be employed in a manner identical tothose supported metal oxides heretofore known in the art and thereforeno detailed discussion of such uses is deemed necessary for a fullunderstanding of the invention.

Numerous modifications and variations of the present invention arepossible in light of the above teachings and therefore the invention maybe practiced otherwise than as particularly described.

What is claimed is:

l. A process for producing a nitrile, comprising:

contacting ammonia with a hydrocarbon selected from the group consistingof alkyl substitued benzenes and alkyl substituted naphthalenes whereinthe alkyl group contains no more than four carbon atoms, isobutylene andpropylene, in the presence of a metal oxide supported on a poroussupport, said support containing from about 25% to about by weight, ofthe metal oxide having been placed in molten form substantially entirelywithin the pores of the support, the support having a surface areagreater than about 50 meter square per gram and a porosity greater thanabout 0.4 cc per gram, said metal oxide being selected from the groupconsisting of vanadia, molybdena and mixtures thereof, and said supportbeing selected from the group consisting of gamma-alumina andsilicaalumina.

2. The process of claim 1 wherein the contacting is effected at atemperature from about 300C to about 500C.

3. The process of claim 2 wherein the mole ratio of ammonia tohydrocarbon is from about 2:1 to about 5:].

4. The process of claim 3 wherein the hydrocarbon is an alkylsubstituted benzene.

5. The process of claim 3 wherein the hydrocarbon is an alkylsubstituted naphthalene.

6. The process of claim 1 wherein the contacting is effected in theabsence of molecular oxygen, said supported metal oxide beingperiodically passed to a separate reaction zone wherein the supportedmetal oxide is contacted with molecular oxygen and recycled to thenitrile production.

7. The process of claim 6 wherein the contacting is effected at atemperature of from about 300C to about 500C.

8. The process of claim 7 wherein the mole ratio of ammonia tohydrocarbon is from about 2:1 to about 5:1.

9. The process of claim 8 wherein the hydrocarbon is an alkylsubstituted benzene.

10. The process of claim 8 wherein the hydrocarbon is an alkylsubstituted naphthalene.

11. The process of claim 8 wherein the hydrocarbon is a xylene.

1. A PROCESS FOR PRODUCING A NITRILE, COMPRISING: CONTACTING AMMONIAWITH A HYDROCARBON SELECTED FROM THE GROUP CONSISTION OF ALKYLSUBSTITUTED BEBZENES AND ALKYL SUBSTITUTED NAPHTHALENES WHEREIN THEALKYL GROUP CONTAINS NO MORE THAN FOUR CARBON ATOMS, ISOBUTYLENE ANDPROPYLENE, IN THE PRESENCE OF A METAL OXIDE SUPPORTED ON A POROUSSUPPORT, SAID SUPPORT CONTAINING FROM ABOUT 25% TO ABOUT 75%, BY WEIGHT,OF THE METAL OXIDE HAVING BEEN PLACED IN MOLTEN FORM SUBSTANTIALLYENTIRELY WITHIN THE PORES OF THE SUPPORT, THE SUPPORT HAVING A SURFACEAREA GREATER THAN ABOUT 50 METER SQUARE PER GRAM AND A POROSITY GREATERTHAN ABOUT 0.4 CC PER GRAM, SAID METAL OXIDE BEING SELECTED FROM THEGROUP CONSISTING OF VANADIA, MOLYBDENA AND MIXTURES THEREOF, AND SAIDSUPPORT BEING SELECTED FROM THE GROUP CONSISTING OF GAMMAALUMINA ANDSILICA-ALUMINA.
 2. The process of claim 1 wherein the contacting iseffected at a temperature from about 300*C to about 500*C.
 3. Theprocess of claim 2 wherein the mole ratio of ammonia to hydrocarbon isfrom about 2:1 to about 5:1.
 4. The process of claim 3 wherein thehydrocarbon is an alkyl substituted benzene.
 5. The process of claim 3wherein the hydrocarbon is an alkyl substituted naphthalene.
 6. Theprocess of claim 1 wherein the contacting is effected in the absence ofmolecular oxygen, said supported metal oxide being periodically passedto a separate reaction zone wherein the supported metal oxide iscontacted with molecular oxygen and recycled to the nitrile production.7. The process of claim 6 wherein the contacting is effected at atemperature of from about 300*C to about 500*C.
 8. The process of claim7 wherein the mole ratio of ammonia to hydrocarbon is from about 2:1 toabout 5:1.
 9. The process of claim 8 wherein the hydrocarbon is an alkylsubstituted benzene.
 10. The process of claim 8 wherein the hydrocarbonis an alkyl substituted naphthalene.
 11. The process of claim 8 whereinthe hydrocarbon is a xylene.